Combustion seal for cylinder liner in internal combustion engines



Aug. 26, 1969 J, D. MOORE ETAL 3,463,056

COMBUSTION SEAL FOR CYLINDER LINER IN INTERNAL COMBUSTION ENGINES Filed July 29, 1968 ELE E 22 so INVENTORS JAMES D. MOORE CHARLES N. FANGMAN E .T. E -4: BY J o f {i 2 g ATTORNEYS United States Patent 3,463,056 COMBUSTION SEAL FOR CYLINDER LINER IN INTERNAL COMBUSTION ENGINES James D. Moore, East Peoria, and Charles N. Fangman, Peoria, Ill., assignors to Caterpillar Tractor Co., Peoria, Ill., a corporation of California Filed July 29, 1968, Ser. No. 748,305 Int. Cl. Fl6j 11/04 U.S. Cl. 92-171 4 Claims ABSTRACT OF THE DISCLOSURE A seal between the flange of a cylinder liner and the inner wall of a recess in a cylinder head which seals by radial outward or expanding pressure rather than compressive pressure between the cylinder head and the liner flange, thus eliminating the necessity for excessive stud loads and excessively rigid cylinder heads.

Background of the invention Conventional seals for combustion gases in internal combustion engines are compressed between the cylinder liner and cylinder head or between the cylinder block and the cylinder head and are dependent upon stud load and rigidity of the head for proper sealing. As greater horsepower is demanded from engines and correspondingly greater combustion pressures, a more pronounced movement and distortion of the cylinder head occurs. Conventional seals do not have the ability to conform to the movements and distortions of the cylinder head which are now experienced and combustion gas leakage occurs. Tightening of the studs to prevent this leakage results in greater stresses in the cylinder liner flange and the ledge area of the block which can lead to cracking damage in either the liner or the block. Making the cylinder head more rigid to withstand the increased combustion pressures adds considerably to the cost and weight of the engine.

It is the object of the present invention to provide a combustion pressure seal for an internal combustion engine which overcomes the above difliculties and which seals by pressure exerted in a radial outward direction rather than pressure in a direction parallel to the axis of the cylinder. Further and more specific objects and advantages of the invention will be made apparent in the following specification wherein reference is made to the accompanying drawing.

In the drawing:

FIG. 1 is a transverse sectional view through the upper portion of a cylinder block and head showing a cylinder liner therein and a seal constructed in accordance with the present invention;

FIG. 2 is a perspective view of seal parts employed in seal shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional View through a part of the seal illustrating one means for assembling the seal into its operative position; and

FIG. 4 is a view like FIG. 3 showing an alternative means for assembling the seal.

Referring first to FIG. 1, a portion of the upper part of an engine cylinder block is shown at with a cylinder head 11 disposed thereabove. The cylinder is shown as having a precombustion chamber 12 which forms no part of the present invention, but the usual intake and exhaust valves are not illustrated in this view. A cylinder liner 13 within which a piston 14 is reciprocably disposed has a flange 16 at its upper end which rests upon the upper deck of the block 10. The cylinder head 11 is formed with an annular recess surrounding and spaced slightly from the outer periphery of the flange 16. The usual cylinder head gasket need not be used with the seal of the present inven- 3,463,056 Patented Aug. 26, 1969 "ice tion but water passages communicating between the block and the cylinder head, one of which is shown at 17, may be provided with seals in the form of O-rings 18.

The seal of the present invention is in the form of an expansible assembly between the outer periphery of the cylinder liner flange 16 and the inner diameter of the recess in the head block. The outer periphery of the flange 16 is provided, as most clearly illustrated in FIG. 3, with a circumscribing groove 20 which receives a two-part metal seal ring in the form of an inner outwardly expansible ring 22 (see also FIG. 2) and an outer seal ring 23. Both rings are provided with split overlapping ends as shown at 24 and 25 respectively in FIG. 2, and the inner ring 22 urges the outer ring 23 into close sealing contact with the inner periphery of the recess in the cylinder head 11.

For assembling the seal rings into their sealing position, the bottom edge of the recess in the cylinder head may be beveled, as shown at 26 in FIG. 3, so that with the liner and seal rings in place within the block, the head may be brought downwardly into position and the beveled portion 26 will engage and press the ring 23 inwardly so that a good fit will result when the head is brought into its lowermost position in contact with the upper edge of the cylinder liner.

An alternate manner of assembling the parts into their operative positions is illustrated in FIG. 4 wherein a third or assembly ring 28 is employed. In this arrangement, the recess in the cylinder head has a counter bore 30. The liner seal rings 22 and 23 are assembled with the assembly ring 28 embracing the ring 23 and holding it in an inwardly compressed position so that the cylinder head may be brought into place over it. As the cylinder head is brought into place, the ring 28 will be engaged and moved downwardly to the position shown in FIG. 4 within the counter bore 30.

With the seal herein disclosed, adequate sealing for very high pressure is obtained without the necessity of applying unusual torque to the head bolts or studs which hold it in place and without the necessity of making an unnecessarily rigid cylinder head.

What is claimed is:

1. In combination with an engine block having a cylinder liner with a flange extending outwardly from its upper portion and overlying the deck of the block, a head for the block having a circular recess overlying said flange, said flange having a groove circumscribing its periphery, and an expansible ring in said groove having sealing engagement with the Wall of said circular recess.

2. The combination defined in claim 1 with a circular spring in the groove behind the expansible ring for urging the ring outwardly.

3. The combination defined in either of claims 1 and 2 in which the circular recess has a beveled edge to engage and constrict the expansible ring as the cylinder head is moved toward the block and liner.

4. The combination defined in either of claims 1 and 2 in which the circular recess is counterbored to provide space near the deck of the cylinder block for reception of a ring shaped constrictor used temporarily to constrict the expansible ring during assembly.

References Cited UNITED STATES PATENTS 1,707,679 4/1929 McDowell 123-4l.84

FOREIGN PATENTS 484,055 4/ 1938 Great Britain.

WENDELL E. BURNS, Primary Examiner US. Cl. X.R. 123-4134, 193 

